unix purge a column in a csv file EXCEPT the first row which contains the header

Dear experts,
I have a CSV file
column1;column2;column3
1;2;3
4;5;6

I want to purge the 2. column, but NOT the header, expected result
column1;column2;column3
1;;3
4;;6

the current command: awk -F";2" 'BEGIN{OFS=";"}{$2="";print}' input.csv>output.csv
purges the 2. columns for all the rows, including the header
but I want the first row being unchanged and only purge the values in the rows containing the data

"NR" here is an internal awk variable that holds the record number (so line 1 is record 1, line 2 is record 2 and so on). If you process more than one file on the command line, use FNR (which is the record number in the current file), since NR counts all of the lines in all of the files being processed in one call to awk.